Aqueous emulsions of vinylacetate-2-ethyl hexyl acrylate-vinyl sulfonic acid terpolymers, and method of preparation



United States Patent AQUEOUS ElllULSItUNS 0F VENYLACETATE 2- ETHiTl.HEXYL ACRYLATE-VINYL SULFUNIC ACi'l) TERPSLYMERS, AND METHOD OF PREP-ARATEON John R. Condom, Lebanon, N.J., and Julius J. Brezinski, St.Alhans, and Howard M. Rife, Charleston, W. Va., assignors to UnionCarbide Corporation, a corporation of New York No Drawing. Continuationof application Ser. No. 64,255, Oct. 24, 1960. This application Dec. 21,1964, Scr. No. 420,103

25 Claims. (Cl. 260-29.6)

This application is a continuation application of copending applicationSerial No. 64,255, entitled Novel Emulsions Suitable for Use inWater-Based Paints, filed Oct. 24, 1960 and now abandoned.

This invention relates to novel aqueous emulsions of vinyl alkanoateinterpolymers suitable for use as binders in water-based paints.

The use of aqueous emulsions of homopolymers and copolymers of vinylalkanoates as binders in water-based paints is known. However, suchemulsions are of limited value since they are incapable of adhering tochalky surfaces, and of producing tough, continuous coatings having goodfilm cohesion and substrate adhesion in the presence of large quantitiesof pigment.

It has now been discovered, in accordance with the instant invention,that stable aqueous emulsions of vinyl alkanoate interpolymers, suitablefor use as binders in water-based paints can be prepared by polymerizinga vinyl alkanoate wherein the acyl group of the alkanoate contains fromtwo to ten carbon atoms, preferably vinyl acetate, with an alkylacrylate wherein the alkyl group contains from six to twelve carbonatoms, preferably 2- ethylhexyl acrylate, and a minor amount of a vinylsulfonate salt in water in the presence of certain anionic and nonionicsurfactants. Such emulsions are characterized by excellent shelf-life,and excellent stability to alternate cycles of freezing and thawing.Films cast from such emulsions are tough and continuous, and arecharacterized by excellent clarity and surface gloss. When suchemulsions are employed in paints, coatings characterized by excellentadhesion to chalky surfaces are obtained therefrom. Paints prepared fromsuch emulsions are capable of producing tough, continuous coatingshaving good film cohesion and substrate adhesion even at pigmentvolumeconcentrations of about 80 percent and higher. Pigment-volumeconcentration is a measure of the amount of pigment (including clays andcoloring matter) employed with a given quantity of binder. It is, ofcourse, desirable to employ paints having as high a pigment-volumeconcentration as possible without sacrificing any of the properties ofthe film obtained from the pigmented system. The pigment-volumeconcentration of a system can be determined in accordance with thefollowing for- Inula:

Pigment-Volume Concentration (percent):

volume of pigment total volume of paint solids The emulsions of theinstant invention are prepared by polymerizing a vinyl alkanoate with analkyl acrylate and a minor amount of a vinyl sulfonate salt, by means ofa polymerization catalyst, in an aqueous solution of certain anionic andnonionic surfactants. Optionally, the emulsion may also contain *awater-soluble buifering agent and a filming aid, which compounds can beadded either before or after polymerization.

Polymerization according to the process of the instant invention can bebrought about my admixing the necessary components of the emulsion andheating the mixture at a temperature of from 65 C. to 90 C., preferablyfrom C. to 82 C. Preferably, polymerization is effected in the absenceof oxygen. Since the polymerization reaction goes essentially tocompletion, all but a very small fraction of the monomers is consumed inthe reaction. Hence the amount of interpolymer present in the finalemulsion is essentially equal to the sum of the charge of the vinylalkanoate, alkyl acrylate and vinyl sulfonate salt employed.

In order to produce the satisfactory emulsions, the components of theaqueous emulsion must be employed therein within certain rather narrowcritical ranges. Thus, the concentration of interpolymer should bemaintained between 50.0 percent by weight to 59.0 percent by weight,preferably from 51.0 percent by weight to 55.0 percent by weight, of thetotal overall weight of the emulsion. When employing a vinylacetate-Z-ethylhexyl acrylatevinyl sulfonate interpolymer, theinterpolymer can be obtained by polymerizing from 37.5 percent by weightto 53.4 percent by weight, preferably from 40.8 percent by weight to47.5 percent by weight, of vinyl acetate with from 4.0 percent by weightto 14.5 percent by weight, preferably from 6.1 percent by weight to 10.8percent by weight, of Z-ethylhexyl acrylate, and] from 0.15 percent byweight to 0.50 percent by weight, preferably from 0.20 percent by weightto 0.35 percent by weight, of the vinyl sulfonate salt, based on thetotal weight of the overall mixture. The interpolymers obtained fromsuch polymerization contain from 86.5 mole percent to 96.2 mole percent,preferably from 89. 6 mole percent to 94.0 mole percent, of combinedvinyl acetate, from 3.8 mole percent to 13.5 mole percent, preferablyfrom 6.0 mole percent to 10.4 mole percent, of combined ethylhexylacrylate, and from 0.11 mole percent to 0.39 mole percent, preferablyfrom 0.15 'mole percent to 0.17 mole percent, of combined vinylsulfonate salt.

As will be evident from the above, only minor amounts of the vinylsulfonate salt are employed in the polymerization and are present in theinterpolymers. The use of greater amounts of such salts is undesirablebecause higher concentrations cause increased water sensitivity of thefilms produced from paints containing such interpolymers. The vinylsulfonate salts which can be employed are the alkali metal and ammoniumsalts of vinyl sulfonic acid, including sodium vinyl sulfonate,potassium vinyl sulfonate, lithium vinyl sulfonate, and ammonium vinylsulfonate.

The choice of anionic and nonionic surfactants employed in the aqueousemulsions of the instant invention is critical since only certainsurfactants will produce stable emulsions capable of being used toproduce water-based paints which closely adhere to chalky surfaces andform tough, continuous coatings having good film cohesion and substrateadhesion even at pigment-volume concentrations of percent and higher.The anionic surfactants which have been found capable of producingsatisfactory emulsions are the alkali metal and ammonium alkyl sulfatesalts wherein the alkyl radicals each contain from 10 to 18 carbonatoms, preferably from 12 to 14 carbon atoms. Typical of the alkylsulfate salts which can be employed are such compounds as sodium decylsulfate, sodium tridecyl sulfate, sodium lauryl sulfate, sodiumtetradecyl sulfate, sodium octadecyl sulfate, potassium decyl sulfate,potassium tetradecyl sulfate, ammonium tridecyl sulfate, ammoniumoctadecyl sulfate, lithium lauryl sulfate and the like. These compoundscan be employed individually or in various combinations thereof. Inorder to produce satisfactory emulsions, the concentration of anionicsurfactant should be maintained between 0.20 percent by .weight to 0.60percent by weight, preferably from 0.25

percent by weight to 0.35 percent by weight, of the total overall weightof the emulsion.

The nonionic surfactants which have been found capable of producingsatisfactory emulsions include certain polyalkylene glycol ethers. Amongthe polyalkylene glycol ethers which can be employed are compounds whichcan be depicted by the general formula:

wherein m, n and o are whole integers having a value sufiicient toimpart an average molecular weight of from 2,000 to 3,500, preferablyfrom 2,500 to 3,000, to the polyalkylene glycol ether, there being from20 percent by weight to 80 percent by Weight, preferably from 30 percentby weight to 50 percent by weight, of CH CH O-- radicals present in saidpolyalkylene glycol ether. Also illustrative of the polyalkylene glycolethers which can be employed are compounds which can be depicted by thegeneral formula:

wherein R represent-s an alkyl radical having from 1 to 8 carbon atoms,preferably from 3 to 5 carbon atoms, and p and q are whole integershaving a value sufiicient to impart an average molecular weight of from2,000 to 3,500, preferably from 2,500 to 3,000, to the polyalkyleneglycol ether, there being from 20 percent by weight to 80 percent byweight, perferably from 30 percent by weightto 50 per cent by weight, ofCH CH O radicals present in said polyalkylene glycol ether. Furtherillustrative of the polyalkylene glycol ethers which can be employed arecompounds which can be depicted by the general formula:

RO-Z--(CH CH -H wherein R represents an alkyl radical having from 1 to 8carbon atoms, preferably from 3 to carbon atoms, Z represents acombination of CH CH O- and radicals containing from 2 percent by weightto 5 percent by weight of CH CH O- radicals, and r is a whole integer,there being a sufficient number of CH CH O and -CH CH(CH )O radicalspresent to impart an average molecular weight of from 2,000 to 3,500,preferably from 2,500 to 3,000 to the polyalkylene glycol ether, andthere being from 20 percent by weight to 80 percent by weight,preferably from 30 percent by Weight to 50 percent by weight, of CH CH Oradicals present in said polyalkylene glycol ether.

In order to produce satisfactory emulsions, the concentration ofnonionic surfactant should be maintained between 0.80 percent by weightto 2.50 percent by weight, preferably from 1.00 percent by weight to2.00 percent by Weight, of the total over-all weight of the emulsion.

Any water-soluble vinyl polymerization catalyst can be employed ineffecting polymerization according to the process of the instantinvention. Typical of the vinyl polymerization catalysts which can beemployed are such compounds as potassium persulfate, ammoniumpersulfate, sodium persulfate, potassium perborate, ammonium perborate,sodium perborate, hydrogen peroxide and the like. These compounds can beemployed individually or in various mixtures thereof. The catalystshould be employed in an amount of from 0.05 percent by weight to 0.25percent by weight, preferably from 0.10 percent by weight to 0.20percent by weight, of the total overall weight of the emulsion.

It has been found that the shelf-life of the aqueous emulsions of theinstant invention can be prolonged beyond a period of 12 months if thepH of the emulsion is maintained between 4.0 and 6.0. Consequently, theuse of a buffering agent is desirable in order to maintain the pH of theemulsion within the recommended range, and any water-soluble bufferingagent which will maintain the pH of the emulsion within this range canbe employed. Typical of the buffering agents which can be employed aresuch compounds as sodium carbonate, potassium carbonate, ammoniumcarbonate, sodium acetate, potassium acetate, sodium bicarbonate, sodiumphosphate, potassium phosphate, ammonium phosphate, sodium tetraborate,potassium tetraborate and the like. These compounds can be employedindividually or in various cornbinations thereof.

The use of a filming aid in the aqueous emulsions of the instantinvention is preferred in order to improve the filming potential of theemulsion at low temperatures, and to improve the compatibility of thevarious ingredients of the emulsion. Any Water-soluble filming aid canbe employed for this purpose. Typical of the filming aids which can beemployed are such compounds as Z-methyl- 2,4-pentane'diol,2-(2-ethoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethyl acetate,2-(2-butoxyethoxy)ethyl acetate, ethylene glycol diacetate and the like.These compounds can be employed individually or in various mixturesthereof. The filming aid should be employed in an amount of from 0.50percent by weight to 2.50 percent by weight, preferably from 0.80percent by weight to 1.50 percent by weight, of the total overall weightof the emulsion.

The various components of the emulsion are, of course, dispersed inwater.

The following examples are set forth for purposes of illustration sothat those skilled in the art may better understand this invention, andit should be understood that they are not to be construed as limitingthis invention in any manner.

EXAMPLE I An admixture of 4.25 grams of sodium vinyl sulfonate, 5.10grams of Sipon WD (sodium lauryl sulfate), 29.70 grams of Tergitol XD (abutoxypolyoxypropylene-polyoxyethylene ethanol), 1.70 grams of potassiumpersulfate, 1.70 grams of sodium carbonate, 17.0 grams of 2-methyl-2,4-pentanediol and 756.3 grams of water was prepared, and sparged withnitrogen to remove oxygen. To the resulting water-clear solution wereadded 44.0 grams of a mixture containing 752 grams of vinyl acetate and136 grams of Z-ethylhexyl acrylate. The resulting mixture was heated ata temperature of 75 C. until the entire monomer charge had polymerized.The remaining 840 grams of the vinyl acetate-Z-ethylhexyl acrylatemixture was then added over a period of two hours while the temperatureof the resulting mixture was maintained at from 78 C. to 82 C. Followingthis, the mixture was heated for an additional hour at a temperature offrom 82 C. to 85 C. to insure complete polymerization.

The resulting emulsion had a concentration of unreacted vinyl acetateand unreacted 2-ethylhexyl acrylate of 0.3 percent by weight and 0.05percent by weight, respectively, a total non-volatile content of 54.2percent by Weight, and a pH of 5.5. The size of the solid particlespresent in the emulsion, as determined by means of an electronmicrograph, ranged from 0.05 to 0.3 micron, with the mean particle sizebeing 0.22 micron. The viscosity of the emulsion, as determined on aBrookfield Viscosimeter, model LVF, at 60 r.p.m. using a No. 4 spindle,was 800 centipoises. The absolute viscosity of the emulsion, asdetermined with a Ubbelohde Viscosimeter on a mixture of 3.6 parts ofthe emulsion in 3.4 parts of water and 93 parts of dimethyl formamidewas 2.9 centipoises.

The emulsion was stored for over 15 months without any noticeable changein viscosity. When a sample of the emulsion was heated at a temperatureof C. for 18 hours, no thickening or coagulation of the emulsionoccurred. When a l00-ml. sample of the emulsion was diluted to a solidsconcentration of 6 percent by weight, less than 0.1 cc. of solidssettled out from the emulsion over a 24-hour period.

A film cast from the emulsion on a black, non-reflecting background wasoptically clear and had a 60 specular gloss of 190 on a Gardner GlossMeter as determined in accordance with A.S.T.M. method D523-53P. Thefilm haze, as determined in accordance with A.S.T.M. DesignationsD1003-52 A.S.T.M. Standards, 1955, pp. 320 326, Procedure A, was lessthan 0.1 percent. A film specimen of three mils thickness, prepared anddried for 72 hours at a temperature of 73 F. and at a relative humidityof 50 percent, could be elongated approximately 300 to 400 percentbefore breakage occurred.

The emulsion was used in the preparation of a waterbased paint. Thepaint was prepared by charging 137.75 grams of Ti-Pure R-100 (rutiletitanium dioxide), 420.14 grams of calcium carbonate, 15.02 grams of a25 percent by weight aqueous solution of Tamol 731 (a pigment dispersantconsisting of the sodium salts of carboxylated polyelectrolytes), 0.39grams of Bubble Breaker 746 (a commercial defoamer), and 230.0 grams ofwater to a pebble mill, grinding the mixture together over a period of18 hours, and then dispersing therein, with agitation, in the orderstated, 19.00 grams of ethylene glycol, 24.37 grams of Carbitol(2-(2-ethoxyethoxy)- ethanol), 79.58 grams of the emulsion prepared inaccordance with the above procedure, 31.17 additional grams of water,and 258.08 grams of a 4 percent by weight aqueous solution of PolyoxWSR-301 (a polyethylene oxide).

The resulting paint had a non-volatile content of 50.7 percent byweight, a pH of 8.3, and a viscosity of 1030 centipoises, as determinedon a Brookfield Viscosimeter, Model LVF, at 60 r.p.m. using a No. 4spindle.

When a sample of the paint was successively frozen at 6 F. for 16 hoursand then thawed at room temperature for 8 hours through three cycles, nothickening or coagulation of the paint occurred. A film from the paintbrushed on a UF-1301 primed Morest chart, after aging for one week,withstood more than 8,000 cycles of scrubbing on a Gardner WashabilityMachine employing a 0.5 percent by weight solution of Ivory soap. Thisindicated the presence of a tough, continuous film.

The pigment-volume concentration of the paint was 80.4 percent.

EXAMPLE II An admixture of 12.0 grams of Tergitol 3 (sodium tridecylsulfate), 36.0 grams of Pluoronic L62 (a polyalkylene glycol ether), 6.0grams of sodium vinyl sulfonate, 2.4 grams of sodium carbonate, 2.4grams of potassium persulfate, 24.0 grams of 2-methyl-2,4-pentanedioland 1069.0 grams of Water was prepared, and sparged with nitrogen toremove oxygen. To the resulting waterclear solution were added 62.4grams of a mixture containing 1060.8 grams of vinyl acetate and 187.2grams of 2-ethylhexyl acrylate. The resulting mixture was heated at atemperature of 75 C. until the entire monomer charge had polymerized.The remaining 1185.6 grams of the vinyl acetate-2-ethylhexyl acrylatemixture was then added over a period of two hours While the temperatureof the resulting mixture was maintained at from 78 C. to 82 C. Followingthis, the mixture was heated for an' additional hour at a temperature offrom 82 C. to 85 C. to insure complete polymerization.

The resulting emulsion had a concentration of unreacted vinyl acetateand unreacted 2-ethylhexyl acrylate of 0.35 percent by weight and 0.05percent by weight, respectively, a total non-volatile content of 54.1percent by weight, and a pH of 5.3. The viscosity of the emulsion, asdetermined on a Brookfield Viscosimeter, Model LVF, at 60 r.p.m. using aNo. 4 spindle, was 1,000 centipoises. The absolute viscosity of theemulsion, as determined with a Ubbelohde Viscosimeter on a mixture of3.6 parts of the emulsion in 3.4 parts of water and 93 parts of dimethylformamide was 2.2 centipoises.

The emulsion was stored for over months without any noticeable change inviscosity. When a sample of the emulsion was heated at a temperature of80 C. for 18 6 hours, no thickening or coagulation of the emulsionoccurred. When a -ml. sample of the emulsion was diluted to a solidsconcentration of 6 percent by weight, less than 0.1 cc. of solidssettled out from the emulsion over a 24 hour period.

A film cast from the emulsion on a black, non-reflecting background wasoptically clear and had a 60 specular gloss of on a Gardner Gloss Meteras determined in accordance with A.S.T.M. method D 52353P. The filmhaze, as determined in accordance with A.S.T.M. Designations D1003-52A.S.T.M. Standards, 1955, pp. 320 326, Procedure A, was less than 0.1percent. A film specimen of three mils thickness, prepared and dried for72 hours at a temperature of 73 F. and at a relative humidity of 50percent, could be elongated approximately 400 percent before breakageoccurred.

The emulsion was used in the preparation of a Waterbased paint. Thepaint was prepared by charging 137.75 grams of TiPure R400 (rutiletitanium dioxide), 420.14 grams of calcium carbonate, 15.02 grams of a25 percent by weight aqueous solution of Tamol 731 (a pigment dispersantconsisting of the sodium salts of carboxylated polyelectrolytes), 0.39grams of Bubble Breaker 746 (a commercial defoamer), and 230.0 grams ofwater to a pebble mill, grinding the mixture together over a period of18 hours, and then dispersing therein, with agitation, in the orderstated, 19.00 grams of ethylene glycol, 24.37 grams of Carbitol(2-(2-ethoxyethoxy)- ethanol), 79.58 grams of the emulsion prepared inaccordance with the above procedure, 31.17 additional grams of water,and 258.08 grams of a 4 percent by weight aqueous solution of PolyoxWSR-30l (a polyethylene oxide).

The resulting paint had a non-volatile content of 50.7 percent byweight, and a viscosity of 1030 centipoises, as determined on aBrookfield Viscosimeter, Model LVF, at 60 r.p.m. using a No. 4 spindle.

When a sample of the paint was successively frozen at 6 F. for 16 hoursand then thawed at room temperature for 8 hours through three cycles, nothickening or coagulation of the paint occurred. A film from the paintbrushed on a UF-1301 primed Morest chart, after aging for one week,withstood more than 8,000 cycles of scrubbing on a Gardner WashabilityMachine employing a 0.5 percent by weight solution of Ivory soap. Thisindicated the presence of a tough, continuous film.

The pigment-volume concentration of the paint was 80.4 percent. Thepaint is useful for indoor coatings.

EXAMPLE III A paste suitable for use in water-based paints was preparedby admixing 128.0 pounds of water with 0.65 pound of Bubble Breaker 746(a commercial defoamer), agitating the mixture at slow speed on alaboratory Model IVG Cowles Dissolver, and then adding, in the orderstated, 8.74 pounds of a 25 percent by weight aqueous solution of Tamol731 a pigment dispersant consisting of the sodium salts of carboxylatedpolyelectrolytes), 0.32 pounds of tetrasodium pyrophosphate, 1.10 poundsof Tergitol NPX (a nonyl phenyl ether of polyethylene glycol), 19.21pounds of ethylene glycol, 185.53 pounds of sifted Tri-Pure R-610(rutile titanium dioxide), 32.74 pounds of sifted Ti-Pure FF (anatasetitanium dioxide), 56.22 pounds of sifted ASP-600 (aluminum silicate),27.31 pounds of sifted Silversheen Special (water ground mica), and20.34 pounds of sifted Lorite (a mixture of diatomaceous silica andcalcium carbonate), and increasing the agitation of the Dissolver to aspeed of 4,400 r.p.m. for twenty minutes.

The paste was used in the preparation of a water based paint. The paintwas prepared by dispersing in a paint mixer, in the order stated, thepaste prepared in accordance with the above-described procedure, 2.60pounds of Bubble Breaker 746, 397.17 pounds of an emulsion prepared in amanner similar to that described in Example I, 4.19 pounds of2-ethylhexyl acetate, 134.09 pounds of a mixture containing 15.90 poundsof Carbitol (2-(2-ethoxyethoxy)ethanol) and 4.59 pounds of TroysanPMA-30 (mildewcide) in 113.60 pounds of water, and 241.60 pounds of asolution of 9.66 pounds of Cellosize WP300 (hydroxyethyl cellulose) and2.17 pounds of Troysan PMA (mildewcide) in 88.17 pounds of water.

The resulting paint had a non-volatile content of 50.1 percent byweight, and a viscosity of 1170 centipoises, as determined on aBrookfield Viscosimeter, Model LVF, at 60 r.p.m. using a No. 4 spindle.The pigment-volume concentration of the paint was 32.2 percent.

The paint, which is useful for outdoor coatings, was applied by means ofa 0.007 clearance blade to a wooden panel having a medium chalkedcoating thereon, and allowed to dry at room temperature for twenty-fourhours. The resulting film was completely out through with a knife in across-hatch pattern, and cellophane tape was applied firmly to thesurface. When the cellophane tape was rapidly pulled away, 100 percentof the film remained adhered to the panel.

The test was repeated employing paints prepared in the manner describedabove but substituting certain commercially available emulsions for theemulsion prepared analogously to the manner described in Example I. Theresults obtained are summarized in Table A below.

TABLE A Percent of film adherence to panel after cellophane r movalResyn 25-2243 20 Lytron 680 Table A clearly demonstrates the superioradhesion of paint coatings prepared from the emulsions of the instantinvention as compared to paint coatings prepared from other emulsions.

What is claimed is:

1. A mixture suitable for use in the preparation of water-based paintsconsisting of:

(a) from 37.5 percent by weight to 53.4 percent by weight of vinylacetate;

(b) from 4.0 percent by weight to 14.5 percent by weight of Z-ethylhexylacrylate;

(c) from 0.15 percent by weight to 0.50 percent by weight of a compoundselected from the group consisting of alkali metal and ammonium salts ofvinyl sulfonic acid;

((1) from 0.20 percent by weight to 0.60 percent by weight of a compoundselected from the group consisting of alkali metal and ammonium alkylsulfate salts wherein the alkyl radicals each contain from to 18 carbonatoms;

(e) from 0.80 percent by weight to 2.50 percent by weight of apolyalkylene glycol ether selected from the group consisting of:polyalkylene glycol ethers represented by the general formula (CH CH O)H wherein m, n and 0 are whole integers having a value sufiicient toimpart an average molecular weight of from 2,000 to 3,500 to thepolyalkylene glycol ether, there being from 20 percent by weight to 80percent by weight of CH CH O radicals present in said polyalkyleneglycol ether; polyalkylene glycol ethers represented by the generalformula wherein R represents an alkyl radical having from 1 to 8 carbonatoms, and p and q are whole integers having a value sufiicient toimpart an average molecular weight of from 2,000 to 3,500 to thepolyalkylene glycol ether, there being from 20 percent by weight topercent by weight of CH CH O radicals present in said polyalkyleneglycol ether; and polyalkylene glycol ethers represented by the generalformula wherein R represents an alkyl radical having from 1 to 8 carbonatoms, Z represents a combination of CH CH O and CH CH(CH )O radicalscontaining from 2 percent by weight to 5 percent by weight of CH CH Oradicals, and r is a whole integer, there being a sufficient number ofand CH CH(CH )O radicals present to impart an average molecular weightof from 2,000 to 3,500 to the polyalkylene glycol ether, and there beingfrom 20 percent by weight to 80 percent by weight of CH CH O radicalspresent in said polyalkylene glycol ether;

(E) from 0.05 percent by weight to 0.25 percent by weight of awater-soluble vinyl polymerization catalyst; and

(g) from 38.65 percent by weight to 48.95 percent by weight of water.

2. A mixture as in claim 1 wherein the mixture also contains awater-soluble buffering agent capable of maintaining the pH of themixture between 4.0 and 6.0, and a correspondingly lesser amount ofWater.

3. A mixture as in claim 2 wherein the mixture also contains from 0.50percent by weight to 2.50 percent by weight of a water-soluble filmingaid, and a correspondingly lesser amount of water.

4. A mixture as in claim 2 wherein the vinyl sulfonic acid salt issodium vinyl sulfonate.

5. A mixture as in claim 3 wherein the vinyl sulfonic acid salt issodium vinyl sulfonate.

6. A mixture as in claim 3 wherein the buffering agent is sodiumcarbonate.

7. A mixture as in claim 5 wherein the buffering agent is sodiumcarbonate.

8. An aqueous emulsion suitable for use in waterbased paints prepared byheating the mixture of claim 1 at a temperature of from 65 C. to C.

9. An aqueous emulsion suitable for use in water-based paints preparedby heating the mixture of claim 2 at a temperature of from 65 C. to 90C.

10. An aqueous emulsion suitable for use in waterbased paints preparedby heating the mixture of claim 3 at a temperature of from 65 C. to 90C.

11. An aqueous emulsion suitable for use in waterbased paints preparedby heating the mixture of claim 4 at a temperature of from 65 C. to 90C.

12. An aqueous emulsion suitable for use in waterbased paints preparedby heating the mixture of claim 5 at a temperature of from 65 C. to 90C.

13. An aqueous emulsion suitable for use in waterbased paints preparedby heating the mixture of claim 6 at a temperature of from 65 C. to 90C.

14. An aqueous emulsion suitable for use in waterbased paints preparedby heating the mixture of claim 7 at a temperature of from 65 C. to 90C.

15. An aqueous emulsion suitable for use in waterbased paints preparedby heating, at a temperature of from 65 C. to 90 C., a mixtureconsisting of:

(a) from 37.5 percent by weight to 53.4 percent by weight of vinylacetate;

(b) from 4.0 percent by weight to 14.5 percent by weight of 2-ethylhexylacrylate;

(c) from 0.15 percent by weight to 0.50 percent by weight of sodiumvinyl sulfonate;

(d) from 0.20 percent by weight to 0.60 percent by weight of sodiumlauryl sulfate;

(e) from 0.80 percent by weight to 2.50 percent by weight of apolyalkylene glycol ether selected from the group consisting of:polyalkylene glycol ethers represented by the general formula wherein m,n and are whole integers having a value suiiicient to impart an averagemolecular weight of from 2,000 to 3,500 to the polyalkylene glycolether, there being from 20 percent by weight to 80 percent by weight ofCH CH O radicals present in said polyalkylene glycol ether; polyalkyleneglycol ethers represented by the general formula wherein R represents analkyl radical having from 1 to 8 carbon atoms, and p and q are wholeintegers having a value sufficient to impart an average molecular weightof from 2,000 to 3,500 to the polyalkylene glycol-ether, there beingfrom 20 percent by weight to 80 percent by weight of CH CH O radicalspresent in said polyalkylene glycol ether; and polyalkylene glycolethers represented by the general formula wherein R represents an alkylradical having from 1 to 8 carbon atoms, Z represents a combination of-CH CH O and -CH CH(CH )O- radicals containing from 2 percent by weightto 5 percent by weight of CH CH O- radicals, and r is a whole integer,there being a sufiicient number of -CH CH O- and -CH CH(CH )O radicalspresent to impart an average molecular weight of from 2,000 to 3,500 tothe polyalkylene glycol ether, and there being from 20 percent by weightto 80 percent by weight of --CH CH O radicals present in saidpolyalkylene glycol ether;

(f) from 0.05 percent by weight to 0.25 percent by weight of potassiumpersulfate;

(g) from 0.05 percent by weightto 0.30 percent by weight of sodiumcarbonate;

(h) from 0.50 percent by weight to 2.50 percent by weight of2-methyl-2,4-pentanediol; and

(i) from 35.85 percent by weight to 48.40 percent by weight of water.

16. An aqueous emulsion suitable for use in waterbased paints preparedby heating, at a temperature of from 65 C. to 90 C., a mixtureconsisting of:

(a) from 37.5 percent by weight to 53.4 percent by weight of vinylacetate;

(1)) from 4.0 percent by weight to 14.5 percent by weight of2-ethylhexyl acrylate;

(c) from 0.15 percent by weight to 0.50 percent by weight of sodiumvinyl sulfonate;

(d) from 0.20 percent by weight to 0.60 percent by weight of sodiumtridecyl sulfate;

(e) from 0.80 percent by weight to 2.50 percent by weight of apolyalkylene glycol ether selected from the group consisting of:polyalkylene glycol ethers represented by the general formula wherein m,n and 0 are whole integers having a value sufficient to impart anaverage molecular weight of from 2,000 to 3,500 to the polyalkyleneglycol ether, there being from 20 percent by weight to 80 percent byweight of -CH CH O- radicals present in said polyalkylene glycol ether;polyalkylene glycol ethers represented by the general formula wherein Rrepresents an alkyl radical having from 1 to 8 carbon atoms, and p and qare whole integers having a value sufiicient to impart an averagemolecular weight of from 2,000 to 3,500 to the polyalkylene glycolether, there being from 20 percent by weight to percent by weight of CHCH O radicals present in said polyalkylene glycol ether; andpolyalkylene glycol ethers represented by the general formula wherein Rrepresents an alkyl radical having from 1 to 8 carbon atoms, Zrepresents a combination of CH CH O and -CH CH(CH )O- radicalscontaining from 2 percent by weight to 5 percent by weight of CH CH O-radicals, and r is a whole integer, there being a suflicient number of--CH CH O- and CH CH(CH )O radicals present to impart an averagemolecular weight of from 2,000 to 3,500 to the polyalkylene glycolether, and there being from 20 percent by weight to 80 percent by weightof -CH CH O- radicals present in said polyalkylene glycol ether.

(f) from 0.05 percentwby weight to 0.25 percent by weight of potassiumpersulfate;

(g) from 0.05 percent by weight to 0.30 percent by weight of sodiumcarbonate;

(h) from 0.50 percent by weight to 2.50 percent by weight of2-methyl-2,4-pentanediol; and

(i) from 35.85 percent by weight to 48.40 percent by weight of water.

17. A process for producing an aqueous emulsion suitable for use inwater-based paints which comprisesformmg a mixture of:

(a) from 37.5 percent by weight to 53.4 percent by weight of vinylacetate;

(b) from 4.0 percent by weight to 14.5 percent by weight of Z-ethylhexylacrylate;

(c) from 0.15 percent by weight to 0.50 percent by weight of a compoundselected from the group consisting of alkali metal and ammonium salts ofvinyl sulfonic acid;

(d) from 0.20 percent by weight to 0.60 percent by weight of a compoundselected from the group consisting of alkali metal and ammonium alkylsulfate salts wherein the alkyl radicals each contain from 10 to 18carbon atoms;

(e) from 0.80 percent by weight to 2.50 percent by weight of apolyalkylene glycol ether selected from the group consisting of:polyalkylene glycol ethers represented by the general formula where m, nand o are whole integers having a value suificient to impart an averagemolecular weight of from 2,000 to 3,500 to the polyalkylene glycolether, there being from 20 percent by weight to 80 percent by weight of-CH CH O radicals present in said said polyalkylene glycol ether;polyalkylene glycol ethers represented by the general formula wherein Rrepresents an alkyl radical having from 1 to 8 carbon atoms, and p and qare whole integers having a value sufficient to impart an averagemolecular weight of from 2,000 to 3,500 to the polyalkylene glycolether, there being from 20 percent by weight to 80 percent by weight ofCH CH O- radicals present in said polyalkylene glycol ether;

and polyalkylene glycol ethers represented by the general formulawherein R represents an alkyl radical having from 1 to 8 carbon atoms, Zrepresents a combination of CH CH O and CH CH(CH )O radicals containingfrom 2 percent by weight to 5 percent by weight of -CH CH O radicals,and r is a whole integer, there being a sufficient number of and -CHCH(CH )O radicals present to impart an average molecular weight of from2,000 to 3,500 to the polyalkylene glycol ether, and there being from 20percent by weight to 80 percent by weight of CH CH O radicals present insaid polyalkylene glycol ether;

(f) from 0.05 percent by weight to 0.25 percent by weight of aWater-soluble vinyl polymerization catalyst; and

(g) from 38.65 per-cent by Weight to 48.95 percent by weight of water;

and heating the admixture at a temperature of from 65 C. to 90 C.

18. A process as in claim 17 wherein the mixture also contains awater-soluble buffering agent capable of main taining the pH of theemulsion between 4.0 and 6.0, and a correspondingly lesser amount ofwater.

19. A process as in claim 18 wherein the mixture also contains from 0.50percent by weight to 2.50 percent by weight of a water-soluble filmingaid, and a correspondingly lesser amount of water.

20. A process as in claim 18 wherein the vinyl sulfonic acid salt issodium vinyl sulfonate.

21. A process as in claim 19 wherein the vinyl sulfonic acid salt issodium vinyl sulfonate.

22. A process as in claim 19 wherein the buffering agent is sodiumcarbonate.

23. A process as in claim 21 wherein the buffering agent is sodiumcarbonate.

24. A process for producing an aqueous emulsion suitable for use inwater-based paints which comprises forming a mixture of:

(a) from 37.5 percent by weight to 53.4 percent by weight of vinylacetate;

(b) from 4.0 percent by weight to 14.5 percent by weight of 2-ethylhexylacrylate;

(c) from 0.15 percent by weight to 0.50 percent by weight of sodiumvinyl sulfonate;

(d) from 0.20 percent by weight to 0.60 percent by weight of sodiumlauryl sulfate;

(e) from 0.80 percent by weight to 2.50 percent by Weight ofpolyalkylene glycol ether selected from the group consisting of:polyalkylene glycol ethers represented by the general formula wherein m,n and 0 are whole integers having a value sufiicient to impart anaverage molecular weight of from 2,000 to 3,500 to the polyalkyleneglycol ether, there being from 20 percent by weight to 80 percent byweight of -CH CH O radicals present in said polyalkylene glycol ether;polyalkylene glycol ethers represented by the general formula RO (CH CH(CH 0 (CH CH O) -H wherein R represents an alkyl radical having from 1 to8 carbon atoms, and p and q are whole integers having a value sufiicientto impart an average molecular weight of from 2,000 to 3,500 to thepolyalkylene glycol ether, there being from 20 percent by weight to 80percent by weight of CH CH O- radicals present in said polyalkyleneglycol ether;

and polyalkylene glycol ethers represented by the general formulawherein R represents an alkyl radical having from 1 to 8 carbon atoms, Zrepresents a combination of -CH CH O- and CH CH(CH )O radicalscontaining from 2 percent by weight to 5 percent by weight of CI-I CH Oradicals, and r is a whole integer, there being a sufficient number ofand -CH CH(CH )O- radicals present to impart an average molecular weightof from 2,000 to 3,500 to the polyalkylene glycol ether, and there beingfrom 20 percent by Weight to percent by weight of -CH CH O radicalspresent in said polyalkylene glycol ether;

(f) from 0.05 percent by weight to 0.25 percent by weight of potassiumpersulfate;

(g) from 0.05 percent by weight to 0.30 percent by Weight of sodiumcarbonate;

(h) from 0.50 percent by weight to 2.50 percent by weight of2-methyl-2,4-pentanediol; and

(i) from 35.85 percent by weight to 48.40 percent by weight of water;

and heating the admixture at a temperature of from 65 C. to C.

25. A process for producing an aqueous emulsion suitable for use inwater-based paints which comprises forming a mixture of:

(a) from 37.5 percent by weight to 53.4 percent by weight of vinylacetate;

(b) from 4.0 percent by weight to 14.5 percent by weight of 2-ethylhexylacrylate;

(c) from 0.15 percent by weight to 0.50 percent by weight of sodiumvinyl sulfonate;

(d) from 0.20 percent by weight to 0.60 percent by weight of sodiumtridecyl sulfate;

(e) from 0.80 percent by weight to 2.50 percent by weight of apolyalkylene glycol ether selected from the group consisting of:polyalkylene glycol ethers represented by the general formula wherein m,n and 0 are whole integers having a value sufiicient to impart anaverage molecular weight of from 2,000 to 3,500 to the polyalkyleneglycol ether, there being from 20 percent by weight to 80 percent byweight of CH CH O radicals present in said polyalkylene glycol ether;polyalkylene glycol ether represented by the general formula wherein Rrepresents an alkyl radical having from 1 to 8 carbon atoms, and p and qare whole integers having a value sufiicient to impart an averagemolecular weight of from 2,000 to 3,500 to the polyalkylene glycolether, there being from 20 percent by weight to 80 percent by weight ofCH CH O radicals present in said polyalkylene glycol ether; andpolyalkylene glycol ethers represented by the general formula wherein Rrepresents an alkyl radical having from 1 to 8 carbon atoms, Zrepresents a combination of -CH CH O and -CH CH(CH )O- radicalscontaining from 2 percent by weight to 5 percent by Weight of -CH CH Oradicals, and r is a whole integer, there being a sufiicient number ofand CH CH(CH )O- radicals present to impart an average molecular weightof from 2,000 to 3,500 to the polyalkylene glycol ether, and there beingfrom 20 percent by weight to 80 percent by weight of CH CH O radicalspresent in said polyalkylene glycol ether;

(f) from 0.05 percent by weight to 0.25 percent by Weight of potassiumper-sulfate;

(g) from 0.5 percent by weight to 0.30 percent by Weight of sodiumcarbonate;

(h) from 0.50 percent by weight to 2.50 percent by weight of 2methyl-2,4-pentanediol; and

(i) from 35.85 percent by weight to 48.40 percent by weight of water;

to 90 C.

References Cited by the Examiner UNITED STATES PATENTS Heuer 260-29.6Wilson 260-29.6 Carlson 26029.6 Maeder 26029.6 Costello 260-296 Budewitz260-29.6

MURRAY TILLMAN, Primary Examiner.

W. J. BRIGGS, SR., Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,318,830 Dated May 9,

John R. Cendon at a].

It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 13, line ).5 sheuld read --C.O5--.

Signed and Scaled this twenty-fifth Day Of November 1975 {SEALI A nest:

RUTH C. M'ASON C. MARSHALL DANN Arrcxling Officer (mnmisximwr 0] Parentsand TFUl/(HIUI'kS FORM PC4050 (10-69] USCOMM-OC BOS'IB-F'GQ us.GOVERNMENT rnnmna OFFICE Ill! o-JGi-su.

1. A MIXTURE SUITABLE FOR USE IN THE PREPARATION OF WATER-BASED PAINTSCONSISTING OF: (A) FROM 37.5 PERCENT BY WEIGHT TO 53.4 PERCENT BY WEIGHTOF VINYL ACETATE; (B) FROM 4.0 PERCENT BY WEIGHT TO 14.5 PERCENT BYWEIGHT OF 2-ETHYLHEXYL ACRYLATE; (C) FROM 0.15 PERCENT BY WEIGHT TO 0.50PERCENT BY WEIGHT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING OFALKALI METAL AND AMMONIUM SALTS OF VINYL SULFONIC ACID; (D) FROM 0.20PERCENT BY WEIGHT TO 0.60 PERCENT BY WEIGHT OF A COMPOUND SELECTED FROMTHE GROUP CONSISTING OF ALKALI METAL AND AMMONIUM ALKYL SULFATE SALTSWHEREIN THE ALKYL RADICALS EACH CONTAIN FROM 10 TO 18 CARBON ATOMS; (E)FROM 0.80 PERCENT BY WEIGHT TO 2.50 PERCENT BY WEIGHT OF A POLYALKYLENTGLYCOL ETHER SELECTED FROM THE GROUP CONSISTING OF : POLYALKYLENE GLYCOLETHERS REPRESENTED BY THE GENERAL FORMULA